diff -r 0705efd9c69e tools/python/xen/xend/XendDomain.py
--- a/tools/python/xen/xend/XendDomain.py	Fri Oct 16 09:04:53 2009 +0100
+++ b/tools/python/xen/xend/XendDomain.py	Mon Oct 19 10:15:06 2009 +0800
@@ -1522,6 +1522,45 @@
             raise XendError("can't write guest state file %s: %s" %
                             (dst, ex[1]))
 
+    def domain_usb_add(self, domid, dev_id):
+        dominfo = self.domain_lookup_nr(domid)
+        if not dominfo:
+            raise XendInvalidDomain(str(domid))
+
+        usb = dominfo.info['platform'].get('usb')
+        if not usb:
+            raise XendError("Can't add usb device to a guest with usb disabled in configure file")
+
+        hvm = dominfo.info.is_hvm()
+        if not hvm:
+            raise XendError("Can't add usb device to a non-hvm guest")
+
+        if dominfo._stateGet() != DOM_STATE_HALTED:
+            dominfo.image.signalDeviceModel("usb-add",
+                "usb-added", dev_id)
+        else:
+            log.debug("error: Domain is not running!")
+
+
+    def domain_usb_del(self, domid, dev_id):
+        dominfo = self.domain_lookup_nr(domid)
+        if not dominfo:
+            raise XendInvalidDomain(str(domid))
+
+        usb = dominfo.info['platform'].get('usb')
+        if not usb:
+            raise XendError("Can't add usb device to a guest with usb disabled in configure file")
+
+        hvm = dominfo.info.is_hvm()
+        if not hvm:
+            raise XendError("Can't del usb to a non-hvm guest")
+
+        if dominfo._stateGet() != DOM_STATE_HALTED:
+            dominfo.image.signalDeviceModel("usb-del",
+                "usb-deleted", dev_id)
+        else:
+            log.debug("error: Domain is not running!")
+
     def domain_pincpu(self, domid, vcpu, cpumap):
         """Set which cpus vcpu can use
 
diff -r 0705efd9c69e tools/python/xen/xend/server/SrvDomain.py
--- a/tools/python/xen/xend/server/SrvDomain.py	Fri Oct 16 09:04:53 2009 +0100
+++ b/tools/python/xen/xend/server/SrvDomain.py	Mon Oct 19 10:15:06 2009 +0800
@@ -225,6 +225,19 @@
         self.acceptCommand(req)
         return self.xd.domain_reset(self.dom.getName())
 
+    def op_usb_add(self, op, req):
+        self.acceptCommand(req)
+        return req.threadRequest(self.do_usb_add, op, req)
+
+    def do_usb_add(self, _, req):
+        return self.xd.domain_usb_add(self.dom.getName(), req)
+ 
+    def op_usb_del(self, op, req):
+        self.acceptCommand(req)
+        return req.threadRequest(self.do_usb_add, op, req)
+
+    def do_usb_del(self, _, req):
+        return self.xd.domain_usb_add(self.dom.getName(), req)
 
     def render_POST(self, req):
         return self.perform(req)
diff -r 0705efd9c69e tools/python/xen/xm/main.py
--- a/tools/python/xen/xm/main.py	Fri Oct 16 09:04:53 2009 +0100
+++ b/tools/python/xen/xm/main.py	Mon Oct 19 10:15:06 2009 +0800
@@ -161,6 +161,9 @@
     'vcpu-set'    : ('<Domain> <vCPUs>',
                      'Set the number of active VCPUs for allowed for the'
                      ' domain.'),
+    #usb
+    'usb-add'     : ('<domain> <[host:bus.addr] [host:vendor_id:product_id]>','Add the usb device to FV VM.'),
+    'usb-del'     : ('<domain> <[host:bus.addr] [host:vendor_id:product_id]>','Delete the usb device to FV VM.'),
 
     # device commands
 
@@ -350,6 +353,8 @@
     "top",
     "unpause",
     "uptime",
+    "usb-add",
+    "usb-del",
     "vcpu-set",
     ]
 
@@ -382,6 +387,8 @@
     "top",
     "unpause",
     "uptime",
+    "usb-add",
+    "usb-del",
     "vcpu-list",
     "vcpu-pin",
     "vcpu-set",
@@ -1473,6 +1480,14 @@
     else:
         mem_target = int_unit(args[1], 'm')
         server.xend.domain.setMemoryTarget(dom, mem_target)
+
+def xm_usb_add(args):
+    arg_check(args, "usb-add", 2)
+    server.xend.domain.usb_add(args[0],args[1])
+
+def xm_usb_del(args):
+    arg_check(args, "usb-del", 2)
+    server.xend.domain.usb_del(args[0],args[1])
     
 def xm_vcpu_set(args):
     arg_check(args, "vcpu-set", 2)
@@ -3311,6 +3326,9 @@
     "tmem-set": xm_tmem_set,
     "tmem-freeable": xm_tmem_freeable_mb,
     "tmem-shared-auth": xm_tmem_shared_auth,
+    #usb
+    "usb-add": xm_usb_add,
+    "usb-del": xm_usb_del,
     }
 
 ## The commands supported by a separate argument parser in xend.xm.